But according to self-made billionaire and "Shark Tank" star Mark Cuban, there's at least one time when you might want to ditch your plastic for cash: During a negotiation.

Cash can be a powerful negotiation tool, he says in a recent interview with Vanity Fair: "I tell people all the time, if you're out — you're going to take a yoga class and they want to charge you $30, say: 'Look, I've got 20 [dollars].' You know what, they're going to take it.

"Negotiating with cash is a far better way to get a return on your investment."

Personal finance expert Dave Ramsey agrees. When you're looking to negotiate a lower price, use cash, he says on The Rachael Ray Show: "Get actual real money because when I put this up in front of you, I have all of your attention right now."

Besides helping you score a better deal, using cold, hard cash can also help you save big by leading you to curtail your spending. That's because researchers have found that paying with cash — physically handing over your money and watching it disappear — is painful.

Simply withdraw a predetermined amount of money for the week or month and commit to spending only that amount. And, if you find yourself in the midst of a negotiation, don't be afraid to flash your cash.